Telephone-transmitter.



PATENTED MAY 1, 1906.

M. SETTER. TELEPHONE TRANSMITTER.

APPLICATION FILED 00181. 1904.

llfzihzefifiej Q 5 Q. m

ins rnn STATES PATENT onricn.

MICHAEL snrrna, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC coMPANY, or crncaeo, ILLINOIS.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented May 1, 1906.

To all wh'om it may concernr.

Be .it known that 1, MICHAEL SETTER, a citizen of the United States of America, and a resident of Chicago, in the countv of Cook and State of Illinois, have invented a certain 'new and useful Improvement in Telephone- Transmitters, of which the following is a specification.

My invention relates to telephone-transmitters of that type in which the necessary variations in resistance of the talking-circuit are roduced by the action of a vibratory diap ragm upon a mass of granular carbon interposed between a stationary back electrode and the vibratory front electrode.

Generally stated, the object of my invention is the provision of an improved and highly efficient telephone-transmitter of the foregoing general character; and a special object is to provide an improved construction of the means for inclosing'the electrodes and granular carbon and of the means for adjustably supporting the stationary or back electrode; and another object is to provide an improved construction and arrangement whereby the diaphragm, the box or inclosure containing the electrodes and granular carbon, and the means for supporting the stationary back electrode may all be organized into a compact structure which is removable as a unit from the casing of the transmitter; and it is also an object, of course, to provide certain details and features of improvement tending to increase the general efficiency and serviceability of a telephone-transmitter of this particular character T o the foregoing and other useful ends my invention consists in the matters hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 is a longitudinal section of a telephone transmitter embodying the rinci les of my-in vention. Fig. 2 shows tihe d' erent'parts in a separate condition of the microphone device which is removable as a unit from the interior of the transmitter-casing. Fig. 3 is a broken detail view showing the arrangement of the damping-springs which bearagainst A the inner surface of the diaphragm. ig. 4 is a detail viewpf the adjustable member to which the rear or stationary electrode is se cured. Fig. 5 is a detail sectional view of the edge or marginal portion of the diaphragm and cover-plate to which the same is secured.

-As' thus illustrated my improved transmitter comprises the usual mouthpiece A, a front plate B, having a threaded opening into which said mouthpiece is screwed, and a shell C, the said front late andshell constituting the casing of t 1e transmitter. The diaphragm D has its edge or marginal portions secured to the perimeter of a concave cover-plate E. This may be accomplished in any suitable manner, but preferably "by means of a sheet-metal ring 6, the same having its edge portions spun over, so as to clamp the diaphragm and cover-plate tightly together. As illustrated, the diaphragm and cover-plate, thus organized into a unitary structure, are insulated from thetransmitten casing by means of one or more layers of insulation F,'the same being applied to the peripheral portions of the said structure.

T e front plate B has its flange 1) internally threaded and adapted to be engaged by the threaded peri hery of a clamping-ring G. It will be seen tliat this clamping-ring is so applied that it clamps the peripheral portions of the diaphragm and cover-plate tightly against the shoulder 1), formed on the interior of the front plate. Screws 0, extending through the flange 1), can be employed for securing the shell (J to the front plate B. \Vith the arrangement shown-a shoet-metal cup H is provided for inclosin the front and back electrodes I and J. The said cu'p can be clamped tightly to the rear surface of'tho diaphragm by means of the nuts 1', applied to the stem i of said front electrode. in this connection it will be seen that the said front electrode may consist of a carbon disk secured to a disk of metal and that the said stem ma be integral with the said metallic disk. in this way the said nuts or other fastening devices serve as the means for securing both the front electrode and the metal cup or inclosure to the back of the diaphragm. The rear or stationary electrode J is preferably of less diameter than the front electrode and may consist of a disk of carbon secured to a disk of metal. Thus constructed the said back electrode may be provided with a relatively large. threaded stem j, which is integral with the said metallic disk. Preferably the said stem is provided with a shoulder y, .A ring of felt j encircles the said stem and is ada ted to beclamped firmly against the r and by then applying clamping and lock nuts ing of the adjustable member .brations are conducted through the moutha washer or clamping-ring f it'being observed that the front. face of the said ring of felt-or other suitable material is preferably flush with the joint between the carbon and metallic disks. Preferably the back electrode and its ring of felt or other suitable material are clamped to a rotary adjustable member j. This can be accomplished by extending the stem j through the central opening of the saidadjustable member 7' In order that the back electrode may be thoroughly insulated from the metal of the transmitter structure, mica washers j and are inter osed between the member j? and the metal washers y' andj", while a ring of insulation 7' is provided in the central openj*.' Thus con-. structed the back electrode is clamped firmly to and insulated from the rotary externallythreaded adjustable member '7', and the felt or other'similar ring is clamped tightly to the back of said electrode. It will be understood, of course, that the said felt ringis of a diameter to fit snugly within the bore or interior of the cup H, so as to effectually seal or inclose the granular carbon and electrodes.

It will be seen that the washer is of a size to bear against the shoulder j. The'threaded portion of the member y" is adapted to engage and screw into the internally-threaded central opening, with which the cover-plate E is provided. In other words, the member 7' is not only an adjustable supportv for the rear electrode, whereby the distance between the two electrodes may. bevaried if such is necessary, but alsoserves as a closure for sealing the chamber provided between the opposing surfaces of the diaphragm and the concave cover-plate. The granular carbon K or other suitable comminuted material is interposed between the opposite faces or surfaces of the two electrodes. Damping-springs L,

secured to the cover-plate by means of screws Z, are adapted to bear upon the back of the diaphragm. In order that it may be readily. adjusted, the rotary member j can be provided with peripheral notches j. As the back electrode is insulated from the metal structure,'vvhile the front electrode is in electrical connection with the diaphragm and cover-plate, it is obvious that one circuit-wire can be attached to the binding-postM, while the other wire can be secured to the stem 3''. In order that it-may be turned readily, the clamping-ring G can be provided with inter-- nal notches g. As a matter of compactness of structure ,the rotary member 1 can be made with a concave or hollow outer surface I adapted to partially, at least, contain the nuts of t e threaded stem The operation is as follows: The voice-vipiece and allowed to impinge upon the face I sliding movement upon its periphery. F urthermore, ,the said felt ring is 'ofcourse more or less flexible and can vibrate with, the cup at its periphery. In'use the action of the electrodes in thismanner serves'to vary the resistancev of the circuit in which the transmitter is included and to thus effect an electrical transmission of the voicevibrations in the well-known manner.- I

- Itwill be seen that the granular carbon and electrodes are effectively inclosed without interfering with the necessary relative vi bration of the two electrodesand that the arrangement for adjustably supporting the back electrode is of an effective and efficient character.v The back electrode and the 1'0- tary member by which it is supported can be removed at will without removing any other portion of the transmitter than the shell C. Also by removing the said shell and the clamping-ring G the diaphragm and cover-' plate and electrodes-and granular carbon can be removed as a unit from the casing of the.

transmitter. This arrangement obviously facilitates the substitution and repair of thedifferent arts and renders the transmitter serviceabl d and reliable in use. cost of manufacturing a transmitter of the foregoing character is comparatively small.

With the construction shown the coverplate E serves as the bridge or support for, the back electrode and also as the means for ef- Again, the

fectually sealing or inclosing the boX containing the granular carbon.

Obviously the sheet-metal binding 6 an stitutes a means for binding or securingtO- gether the peripheral portions of the dia- I phragm and cover-plate, and the two when" astened together cannot be separated that' is, except by ripping off the said 'sheet-metal binding. With this arrangement it is desirable that the central opening in the cover plate be large enough to permit the ready re moval of the carbon-holder H. In other; words, the openingin the backof the unit composed of the diaphragm and cover-plate is large enough to permit the ready removal of the two electrodes and granular carbon and vibratory cup or carbon-holder.

What I claim as my invention is' 1. A telephone-transmitter comprising a casing, a diaphragm, a support secured to the diaphragm, a vibratory front electrode secured to the diaphragm, a stationary back electrode secured to the said support, ,granus lar carbon between said electrodes, and means for holding or inclosing the granular carbon, the said diaphragm, support, electrodes, carhon-holding means and granular carbon being inclosed within said casing, and the same being organized into a structure which is removable as a unit from the interior of said casing the means for holding or inclosing the granular carbon being vibratory with the diaphragm and removable with the electrodes through an opening in the back of said unit.

2. A telephone-transmitter comprising a casing, a diaphragm, a vibratory front electrode, a stationary back electrode, granular carbon between the two electrodes, means for holding or inclosing the granular carbon, together with a cover-plate upon which said backelectrode is mounted, the said dia-.

phragm, electrodes, cover plate, carbonholuing means and granular carbon being organized into a structure which is removable as a unit from the interior of said casing the means for holding or inclosing the granular carbon being vibratory with the diaphragm and removable with the electrodes through an opening in the back of said unit.

3. A telephone-tr'ansmitter comprising a casing, a diaphragm, a cover-plate having its perimeter secured to the edge of said diaphragrn, a vibratory front electrode secured to the diaphragm, a stationary back electrode mounted in and removablethrough an opening in the center of said coverlate, and granular carbon between the twoe ectrodes, said operative elements being removable as a unit from the interior of said ca'sin together with a vibratory carbon-holder a apted for removal through the said opening.

-i.' A telephone-transmitter comprising a diaphragm, a concave cover-plate having its perimeter secured to the marginal ortions of said diaphragm, said cover-plate being provided. with a central opening, a vibratory front electrode secured to the diaphragm, a stationary back electrode mounted in andrer movable through the said opening in the cover-plate, and granular carbon between the two electrodes together with a vibrator carbon-holder adapted for removalthrougii the said opening.

5. A telephone-transmitter comprising a diaphragm, a concave cover-plate having its perimeter held in engagement with the marginal portions of said dia hragm, said cover plate having a contra opening through which access may be had to the fully-inriosed space provided between the. diaphragm and cover-plate, .a closure for said opening, a vibratory front electrode secured .to the diaphragm, a stationary back-elec trode removably secured to said closure, and granular carbon between the two electrodes together with a vibratory carbon -holder adapted for removal through the said openmg;

6. A telephone-transmitter comprising a diaphra m, a sheet-metal binding, a concave co'ver-piate having its perimeter held in en-.

gagement with the marginal ortions of the diaphragm by the sheet-meta binding, a vibratory front electrode carried by the diaphragm, a stationary back electrode carried y the said cover-plate, granular carbon between the two electrodes, a casing provided with a shoulder, and a clamping-ring for clamping the marginal portions of the coverplate and diaphragm against the said shoul- 7.. A telephone-transmitter comprising a diaphragm, a support bridging the back of the diaphragm, a vibratory front electrode secured to thediaphragm, a stationary back electrode mounted in and removable from the transmitter through an opening in the center of said support, and granular carbon between the two electrodes together with a vibratory carbon-holder adapted for removal throu h the said opening.

8. telephone -transmitter comprising a diaphragm, a sheet-metal binding, a concave cover-plate having its perimeter secured to the marginal portions of said diaphragm by the sheet-metal binding, a casing providing a chamber from which the said diaphragm and cover-plate are removable as a unit, and a resistance-bearing device within the fullyinclosed space provided between the diaphragm and cover-plate.

9. A telephone-transmitter comprising a diaphragm, a support bridging the back of the diaphragm, a sheet-metal cu a vibrator front electrode clamping t e bottom wal of said cup to the back of said diaphragm, a stationary back electrode provided with a shoulder, a ring of soft fibrous material encircling the rear portion of said back electrode and closing the mouth of said cup, granular carbon between the two electrodes, screw-threaded means for clampin the said ring against the shoulder on the. sai

back electrode, and means for removably mounting said back electrode in thesaid sup- 10. A telephone-transmitter comprising a front plate, a diaphragm, a vibratory metal cup, a vibratory front electrode secured to the back of said diaphragm, a concave coverplatehavin its perimeter held in engagement with the marginal ortions of said diahragm, and with said front plate, the said front electrode being electrically connected with said cover-plate through the medium of said diaphragm, a stationary back electrode removably mounted in the central ortion of said cover plate but insulated t erefrom, said cover-plate being provided at its center with an opening through whichthe cup and both electrodes are removable from the chamber provided between the diaphragm and cover-plate, whereby the cup and electrodes canbe removed without separating the front and'cover plates.

11.. A telephone-transmitter comprising a front plate, a mouthpiece removably secured to the center of said front plate, a shell removably secured to the periphery of said front plate, a diaphragm, a support secured to and bridging the back of the diaphragm, a vibratory front. electrode secured to the diahragm, a stationary back electrode carried y the said support, and granular carbon between the two' electrodes, said diaphragm,

support, electrodes, and granular carbon be-.

ing organized into a structure ,which is removable as a unit from the chamber provided by the said front plate and shell together With a vibratory carbon-holder adapted for removalthrough the said-opening. 1

.12; A telephone-transmitter comprising a diaphragm, a concave cover-plate having its perimeter secured to the marginal portions of saiddiaphragm, a casing, means for insulate "ing the diaphragm and cover-plate from the casing, a vibratory front electrode secured to the diaphragm, a stationary back electrode removably. mounted'.in said cover-plate,

granular carbon interposed between the two electrodes,' damping-springs secured to the cover-plate and bearing-against the back of the diaphragm, and a clamping-ring for hold ing' the unit-like structure comprising the of the cover-plate and bearing against the said diaphragm. I

14. A telephone-transmitter comprising a diaphragm, a concave cover-plate covering the back of said diaphragm, said 'late' having an internally-threaded centra opening, a vibratory front electrode carried b the diaphragm, a peripherally-threaded c osure screwed into said opening and cover-plate, a

stationary back electrode removably secured to said closure, and granular carbon between the two electrodes together with a vibratory carbon-holder adapted for removal through.

the'said opening.

Signed by me at Chicago, Cook county,

Illinois. this 25th day of October, 1904.

MICHAEL SETTER. Witnesses:

A. E. KEITH, R. C. GIFFonD. 

